I'm about to put some Redline MT-90 in the transmission of my '88 GTU. I just bought the car and it came with no service history and from talking to the second owner, I doubt the gear oil has been changed in a very long time. In fact, this is a low enough mileage car that I wouldn't be surprised if the 1988 oil was still in there.

If it looks dirty when it comes out, should I "flush" it out before putting in the new Redline oil? For example, should I put in something along the lines of a cheaper dino 90W oil and run it for a few hundred miles before switching to the Redline?

(By the way, I searched and read many threads on tranny oil changes and didn't see an answer to this question.)

 

Make certain the car is level, let it drain completely, then just add the Redline.

 

Yeah, I guess if it really looks nasty, I may just decide to replace the Redline sooner than 3 years/30,000 miles with more of the same after this batch has had a chance to clean things up.

 

I would do what you said, do something less expensive for a few hundred miles then change it, perhaps the valvoline synthetic blend.

 

Hi David,

long time since we have chatted.
I would just use the Redline and change it sooner if it has left some residue in the tranny.
Bye the way what happened to the 90 GTU ?
I still have my 1989 GX here in Canada.

pm me if you can
Thanks Paul

 

Thanks for the input Tehmonkay. I think if it looks really sludgy, I may opt for some cheap gear oil for a few hundred miles, but if it looks OK I may forge right ahead with the Redline. I have a feeling I'll sleep a little better doing a second tranny oil change in a few hundred miles and it seems a shame to waste $30 worth of MT-90.

Hey Paul, nice to hear from you. The '90 GTU is still here rusting and crumbling away in my driveway. I plan to get rid of it by the end of March if possible. I'll give you more details in a PM.

-David